Hi, Michael, Marc is correct. The trial is indeed good for 90 days, though OneCare will nag you to purchase on a regular basis. If you answered the nag, signed in and provided payment information, you subscribed - effectively ending your trial period. If this is not what you intended, you can contact customer service to cancel and obtain a refund, but you will not be able to get a 90 day trial period again - only 15 days at a time before you need to reinstall - since OneCare was already on the computer.
Support hours for phone and chat support (as well as availability of both) varies by region.
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
Also, check your email (the yahoo account shown in your profile) as I've just sent you an email.
-steve